import 'package:flutter_test/flutter_test.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:tm_app/core/network/network_manager.dart';
import 'package:tm_app/core/utils/result.dart';
import 'package:tm_app/data/repositories/company_ai_repository.dart';
import 'package:tm_app/data/repositories/home_repository.dart';
import 'package:tm_app/data/services/company_ai_service.dart';
import 'package:tm_app/data/services/home_service.dart';
import 'package:tm_app/data/services/liked_tenders_service.dart';
import 'package:tm_app/data/services/model/recommended_tenders_data/recommended_tenders_data.dart';
import 'package:tm_app/data/services/model/recommended_tenders_response/recommended_tenders_response.dart';
import 'package:tm_app/data/services/model/tender_data/tender_data.dart';
import 'package:tm_app/data/services/your_tenders_service.dart';
import 'package:tm_app/view_models/ai_recommendations_view_model.dart';

void main() {
  group('AiRecommendationsViewModel', () {
    test('loads recommended tenders from GET /api/v1/tenders/recommend', () async {
      final prefs = await _prefs();
      final homeRepository = _FakeHomeRepository(
        prefs,
        result: Result.ok(
          RecommendedTendersResponse(
            succes: true,
            message: 'ok',
            error: null,
            data: RecommendedTendersData(
              tenders: [_sampleTender(id: 'tender-1', title: 'Bridge repair')],
              metadata: null,
            ),
          ),
        ),
      );
      final viewModel = AiRecommendationsViewModel(
        companyAiRepository: _FakeCompanyAiRepository(prefs),
        homeRepository: homeRepository,
      );

      await viewModel.loadRecommendations();

      expect(viewModel.hasLoaded, isTrue);
      expect(viewModel.errorMessage, isNull);
      expect(homeRepository.recommendedTendersCalls, 1);
      expect(viewModel.recommendedTenders.single.id, 'tender-1');
    });

    test('keeps failed transient loads retryable for loadIfNeeded', () async {
      final prefs = await _prefs();
      final homeRepository = _FakeHomeRepository(
        prefs,
        results: [
          Result.error(Exception('network failed')),
          Result.ok(
            RecommendedTendersResponse(
              succes: true,
              message: 'ok',
              error: null,
              data: RecommendedTendersData(
                tenders: [_sampleTender(id: 'tender-1', title: 'Bridge repair')],
                metadata: null,
              ),
            ),
          ),
        ],
      );
      final viewModel = AiRecommendationsViewModel(
        companyAiRepository: _FakeCompanyAiRepository(prefs),
        homeRepository: homeRepository,
      );

      await viewModel.loadRecommendations();
      await viewModel.loadIfNeeded();

      expect(homeRepository.recommendedTendersCalls, 2);
      expect(viewModel.hasLoaded, isTrue);
      expect(viewModel.errorMessage, isNull);
      expect(viewModel.recommendedTenders.single.id, 'tender-1');
    });

    test(
      'marks empty results as still learning after recent onboarding',
      () async {
        final prefs = await _prefs();
        final viewModel = AiRecommendationsViewModel(
          companyAiRepository: _FakeCompanyAiRepository(
            prefs,
            lastOnboardingStartedAt: DateTime.now().millisecondsSinceEpoch,
          ),
          homeRepository: _FakeHomeRepository(prefs),
        );

        await viewModel.loadRecommendations();

        expect(viewModel.hasLoaded, isTrue);
        expect(viewModel.stillLearning, isTrue);
        expect(viewModel.isEmpty, isTrue);
      },
    );
  });
}

Future<SharedPreferences> _prefs() async {
  SharedPreferences.setMockInitialValues({});
  return SharedPreferences.getInstance();
}

class _FakeCompanyAiRepository extends CompanyAiRepository {
  _FakeCompanyAiRepository(
    SharedPreferences prefs, {
    int? lastOnboardingStartedAt,
  }) : _lastOnboardingStartedAt = lastOnboardingStartedAt,
       super(companyAiService: _UnusedCompanyAiService(prefs), prefs: prefs);

  final int? _lastOnboardingStartedAt;

  @override
  int? lastOnboardingStartedAt() => _lastOnboardingStartedAt;
}

class _FakeHomeRepository extends HomeRepository {
  _FakeHomeRepository(
    SharedPreferences prefs, {
    List<Result<RecommendedTendersResponse>>? results,
    Result<RecommendedTendersResponse>? result,
  }) : _results =
           results ??
           [
             result ??
                 const Result.ok(
                   RecommendedTendersResponse(
                     succes: true,
                     message: 'ok',
                     error: null,
                     data: RecommendedTendersData(tenders: [], metadata: null),
                   ),
                 ),
           ],
       super(
         homeService: HomeService(networkManager: NetworkManager(prefs)),
         yourTendersService: YourTendersService(
           networkManager: NetworkManager(prefs),
         ),
         likedTendersService: LikedTendersService(
           networkManager: NetworkManager(prefs),
         ),
       );

  final List<Result<RecommendedTendersResponse>> _results;
  int recommendedTendersCalls = 0;

  @override
  Future<Result<RecommendedTendersResponse>> getHomeRecommendedTenders({
    required int limit,
    required int offset,
  }) async {
    final index = recommendedTendersCalls;
    recommendedTendersCalls += 1;
    return _results[index];
  }
}

class _UnusedCompanyAiService extends CompanyAiService {
  _UnusedCompanyAiService(SharedPreferences prefs)
    : super(networkManager: NetworkManager(prefs));
}

TenderData _sampleTender({required String id, required String title}) {
  return TenderData(
    success: null,
    message: null,
    id: id,
    tenderId: id,
    noticePublicationId: null,
    noticeTypeCode: null,
    formType: null,
    noticeLanguageCode: null,
    issueDate: null,
    issueTime: null,
    publicationDate: null,
    title: title,
    description: null,
    procurementTypeCode: null,
    procedureCode: null,
    estimatedValue: null,
    currency: null,
    duration: null,
    tenderDeadline: null,
    submissionDeadline: null,
    applicationDeadline: null,
    submissionUrl: null,
    countryCode: null,
    durationUnit: null,
    buyerOrganization: null,
    lots: null,
    officialLanguages: null,
    status: null,
  );
}